BoilerFaultCodes 63:0 Medium
Boiler Fault Code 63:0
Also written as 630 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 63:0 appears across 1 boiler brand and 5 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is struggling to correctly communicate with its internal control system regarding how it should heat your hot water tank. (As reported on Viessmann Vitodens 300-W)
Pick your boiler brand for the 63:0 fix
Source
Information for the 63:0 fault code is sourced from the official service / installation manual for each model that displays it. Read more about how we source fault codes →
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026